This judgment, indeed, chiefly affects the neptunian system; but, he has not altogether forgotten the plutonian, which perpetually replaces a perishing system of the globe with a new one, by "the "mere laws of nature:" "The growth of new

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systems out of old ones," says he, "without the "mediation of a DIVINE POWER, seems to ME apparently absurd'." Neither will "the new geogony, which (we are told) has a tendency to lean to the idea of the liquified masses ascending "from below upwards, whereas the ancient geogony explained every thing by precipitation, " and movements in an opposite direction*, escape any better from the overwhelming weight of Newton's condemnation.

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Third Letter to BENTLEY.

'HUMBOLDT, Superpos. of Rocks, p. 414.

CHAPTER IV.

SOME very recent and eminent geological writers have adopted the course, of prudentially excluding from their disquisitions all consideration of the 'unphilosophical" or "absurd" speculations on the MODE of primitive formations, which we have just witnessed; but then, they have at the same time excluded all consideration of the question itself, leaving their geologies without any basis or root, and standing among the other systems of human science, as the air-plant stands among the rooted systems of vegetation. Such mere exclusions, are but weak and timid evasions of a question of primary and fundamental concernment to the truth of geology; and leave the mind in ignorance of that truth, and consequently, the adverse error free to extend its operation in unresisted, because in unregarded, progress. The question, of the MODE of primitive formations, is essential to geology; and may not be excluded, merely because some theorists have proposed " unphilosophical" or "absurd" solutions of it: we are not, therefore, simply to exclude those solutions, but we are to replace them with a solution which shall be conformable to philosophy and sense. There is a third course, besides losing our way in a fog, and standing still in a fog; and that is, to get out of it, and above it, into a

clear and luminous atmosphere. The authors of the speculations, follow the first course; they who merely evade them by silence, follow the second course: the third, is open to those who resolutely rise above them into the brightness of authenticated truth, and who are thus enabled to see and observe the whole circuit of the cloud in which the others remain involved1. The first of these, build their geological structures on a false foundation; the second, build them on none-in the air; the third, will found them in an immoveable rock, whose solidity is susceptible of demonstration.

It will, therefore, be important to the prosecution of our inquiry into the MODE of primitive formations, to investigate preliminarily, with some minuteness, the ground of the opposition of doctrine between the philosophies of Newton and of the mineral geology, respecting a chaotic or fluid state of this globe; and to observe, how deeply the foundation of that opposition is laid.

When Newton had remarked, that the planets present to the sight figures of obtuse spheroids, and not of perfect spheres; when he had reflected upon the nature and properties of that peculiar figure, and had contemplated those orbs as subjected, in their

'The Reviewer of D'Aubuisson's Traité de Géognosie in the Bibliotheque Universelle, passes over the first part of that work, deeming it, as it would appear, too speculative. Yet, its speculation is directed to one of the sublimest and most important objects that can engage the intellect, viz.— the MODE of primitive formations. That object, however, the Reviewer lets pass sub alto silentio; without an attempt to extricate himself from the cloud, in which it is manifest he feels himself involved.

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revolutions, to the adverse actions of gravity and centrifugal force; his penetrating mind at length discovered, that the rule of harmony and equilibrium between those two contending powers, was only to be found in the figure of an obtuse spheroid. To render this fact plain to the understanding of others, he imagined this hypothetical illustration." If,” said he, "the earth were formed of an uniformly yielding substance, and if it were to become deprived of its motion,—si terra constaret ex uniformi materia, motuque omni privaretur1;" the law of gravity, acting equally, and without resistance, from all points of its surface towards its centre, would cause that yielding substance to settle into the figure of a perfect sphere. But, if it were then to receive a transverse impulse which should cause it to revolve upon its axis, the new transverse force would counteract the former force of gravity, by urging the particles composing the yielding substance from their centre towards their circumference; and, would thus produce an alteration in the figure of the sphere. For, the new force would tend to elevate the surface, and would have most power at the equator and least at the poles; whereas, the opposite force of gravity would tend to depress the surface, and would have most power at the poles and least at the equator. The result of this inequality of gravitation, must necessarily be; that the original sphere becoming elevated at the equator, but

1 Princip. Math. lib. iii. prop. 19. prob. 3.

not at the poles, and the elevating power gradually diminishing from the equator to the poles, its figure would be eventually changed into that of an obtuse spheroid.

It being thus shewn, that such would be the necessary result of the compound power of gravity. and centrifugal force; it followed, that those two antagonist forces, acting at the same time in the earth supposed to be formed of an homogeneous and uniformly yielding substance, would work themselves into harmony and equilibrium by producing that figure; which they should thenceforward maintain. Whereas, if we suppose the case of a true sphere, which should consist of a solid and resisting substance; the two forces must act in perpetual and violent discord and conflict, with a constant tendency to disunite and rend the texture of the fabric. Now, Newton, maintained, "that GOD at the beginning "formed all material things, (and therefore this "earth which is one of them,) of such figures and

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properties as most conduced to the END for which "HE formed them," and, having demonstrated, that the property of an obtuse spheroid was that which most conduced to the END for which God formed the earth, he left it to the capacity of every one to draw the obvious inference, in conformity to his known principles,—viz. that it is highly probable, that God has formed the earth with the same figure which it is manifest He has given to the other planets, and for which an ADEQUATE REASON is thus rendered plain to the intelligence. And he confirmed